no, this is not supported - the calculations to perform live stacking for deep sky typically take from 0.25s to several seconds (depending on resolution). This is far too slow for planetary imaging where you want to be running at about 30fps. The only real stacking option for planetary imaging is to capture a video and stack afterwards. Maybe when computers get another 10 times faster or so we can try live planetary stacking!

I think you can already do it if you switch off "Align frames", and as Robin says if your computer is fast enough and your frame rate slow enough. It is useful for non-astronomical imaging to see the image build up in real time, but then my frame rates are much less than 30fps and my FOV is steady.
Alan.

Thanks for the prompt responses. I am blown away by the Live Stack mode for DSO. Live Stacking is a bit hit at our outreach pblic viewing sessions. I know that planetary Live Stack would be challenging but boy if you could pull it off...….